The classic 9173 CPU spikes, might be graphic ?

[Guilla]

Hello everyone,

I am sorry to bring that subject to the table again, I really wish I won't...

My setup :
Macbook Pro i7 mid 2015. 16 Go Ram, 512 Go SSD. OSX Sierra 10.12.1
Mixing from a 512 Go external SSD.
Apollo Silver rack as an interface (although changing interfaces or using PT aggregate does not help).
Pro Tools 12.6.1

I am having constant CPU spikes at the end of mixing sessions.
I have tried a lot of things :
- All the Avid optimisations.
- Disabling Hyper-Threading.
- Stopping the Hard Drive to sleep.
- Removing plugins one by one to find a culprit.
- Trashing pref.
- Deleting computer cache (booting in safe mode).
- No Dynamic Plugin Processing.
- Changing Disk Cache Size.
- No Wifi or Bluetooth when using Pro Tools.
- All size of buffer (keeping the highest buffer seems to work best, no surprise so far).
Etc...

And it is still a nightmare.
The workaround I have found was to reduce the PT windows. That way I can print the stereo mix with a lot less CPU spikes.
Everytime I load a graphic type of plugin ala Fab Filter Pro Q2, with live graphic display, it increases the CPU spikes. If I use the same plugin without the analyzer display it reduces them.
I seem to have less CPU spikes in mixer view. Especially if I push the mixer window down the screen so I can only see the top half of it.

Also it seems (I am not sure here it is hard to tell) that the more auxes I create, the harder it is to avoid those CPU spikes. Especially when comes the time to create a mixbus with some processing on.

I have tried different display scale (bigger,smaller...), it did not change anything.

I know 9173 are as common as curry in India. And that some of you found a solution and others live with them, accumulating anger and frustraion in their heart.

So I was wondering if some of you had similar situations (I guess so) and if you find a solution.
I am really getting desperate about this...
I even tried updating to the last Pro Tools version to date, even the HD version (I am not HD, which sucks when using outboard by the way). And I saw no improvements what so ever...

Thanks to all of you that might chime in to help...
Thx !!